While unfilled orders piled up, a new warehouse management system was installed; 150 warehouse employees went through training; the marketing team sent out cheerful messages about "big, bright and shiny new things happening"; and the customer care staff chatted up shoppers wondering if that cute dress would show up in time for the party.

They all got through it.

"I call that a time investment," said Scott Casciato, the company's vice president of service, in a recent interview at the 220,000-square-foot distribution center in Crafton, Pa.

Modcloth doesn't have brick-and-mortar stores. Shutting down the systems set up to package online orders in boxes and ship them off is like putting a "Closed" sign on the front door of a mall store, something that consumers accustomed to shopping in their pjs at midnight aren't used to dealing with.

Since the beginning, the retailer launched by Carnegie Mellon University grads in 2006 has shot up like a teenager in a growth spurt, expanding from a house to a small warehouse to its current cavernous warehouse, plus offices in Los Angeles and San Francisco.

Orders have always been taken online and filled in Pittsburgh, but the fulfillment processes didn't always expand efficiently.

Customers don't exactly stop shopping in August. That just seemed as good a time as any to get changes in place in time for the crush of the holiday season when the 5,000 to 8,000 boxes typically shipped out daily is expected to triple.

ModCloth's distribution center brings in merchandise daily — the warehouse holds 35,000 different items, with 350 to 450 new ones introduced weekly — and the building is a maze of conveyor belts, boxes, shelves and people handling different pieces of the shipping process while listening to whatever music someone has turned on in their department.

"This department typically has the best music," said Jim Mason, director, fulfillment and logistics, as he walked through the returns area where staffers were breaking down boxes and sending items off to be examined to see if they were in retail condition and ready to find a new owner.

Returns are a part of online retail reality, as customers can't try things out until they have them in their hands.

Another truth of the technology revolution changing the nation's retail industry is that while some customers never leave their homes or interact with any staff at a store, it still takes a lot of people to enable online shopping.

ModCloth planned to hire more than 100 more people at the warehouse between mid-October and mid-November, and Casciato said a significant number of those jobs might convert to full-time positions.

The company employs about 250 in Pittsburgh, with close to 400 workers total.

Getting the $79.99 Luck Be A Lady in Blossom blue floral dress, the $179 shoes with heels shaped like gnomes, and the $14.99 Place of Peace silver necklace with a blue rhinestone into the right storage bin and then into the right order all comes down to the worker on the floor knowing where to go and what to do.

That was key in choosing the new ModCloth warehouse management system, said Casciato. The company tried to choose a system that seemed to work intuitively.

"It doesn't matter how effective you think it can be. It only matters that the people can use it," he said.

Several weeks in, the value of the new warehouse management system already seems proven. The company calculates it has recorded a 20 percent increase in productivity for employees tasked with picking items out to place in boxes for customers.

"We wanted the system years ago," said Casciato, but first up was investing in a financial program that could support the ebb and flow of thousands of transactions from around the country and beyond.

Once that was done, Modcloth could move on to wrestle the warehouse operation into a more efficient, more trackable process.

In Crafton, piles of goods from vendors come through eight docking doors where trucks are emptied. The items are moved directly to be processed by the quality control staff stationed nearby.

Mannequins stand ready to be used so sizing can be checked along with hems, color and other pertinent details.

Not far away, photo studios style and photograph the new stuff for the website and through social media — an online retailer's showroom floor.

The distribution center has segments devoted to rows of shelves filled with products, as well as areas devoted to orders being assembled.

Modcloth's previous smaller sites could get away with using less formal processes. But the move to Crafton in 2012 exposed their weaknesses. "When we moved to a larger location, our associates were walking up to 10 miles a day" filling orders, Mason said.

Even before making the latest management system improvements, the company introduced other changes to ease the flow. For example, it uses technology that calculates how a group of items will fit into each box, identifying what size box will be needed for an order.

Seventy-five percent of the orders filled at the distribution center go into either 12-inch boxes or 18-inch ones.

A bulk picking practice called "waves" lets workers chip away at 10 or more different orders at a time, preferably ones with similar items.

With the new warehouse management system, ModCloth can now track each and every item brought in, identifying the section, aisle and even column post near the bin holding the merchandise.

The new system is sophisticated enough that Casciato dreams of a day when ModCloth could automatically identify new customers and package their order differently to welcome the first-time shopper. Other customization might be possible, as seasons change or certain customer preferences are identified.

An important factor in investing in the new system is that it could easily incorporate growth, if ModCloth ever decides it need more distribution centers. Casciato said management wanted "a highly scalable fulfillment function."

"These systems are systems you use for decades," he said.

The investment came even as ModCloth has been dealing with a bumpy economy and sales issues.

The company recently had a round of layoffs, confirmed Aire Plichta, senior fashion press specialist, in an email about a week after helping with a tour of the warehouse in October. The cuts mainly hit the San Francisco office, she said, adding that the online retailer is strengthening, and in some cases, growing its Pittsburgh operation.

"While our company is still growing faster than the industry as a whole, we have been impacted by the broader downturn affecting the retail sector," said Plichta.

"As a startup, it is in our DNA to remain nimble and these cuts will allow us to return to profitability."

Meanwhile, ModCloth picked up a new Crafton neighbor this fall, further evidence of both the tech shift changing retail and of online merchants' intensified push to ensure goods are delivered as quickly as possible. Online powerhouse Amazon, the ModCloth staff noted, has set up a distribution center next door.